Conceição Correia Ana Claudia, de Melo Oliveira Isadora, De Santana Tauan Rosa, Leal Pollyana Caldeira, Faria-E-Silva André Luis
Int J Esthet Dent. 2020;15(4):490-502.
This study assessed the changes in color and translucency of dentin and enamel after staining and bleaching procedures as well as the contribution of the tissues to color change (CTCC).
Fifty enamel-dentin specimens were obtained from bovine incisors and grouped into 10 blocks based on the similarity of the baseline color. One specimen in each block was used as the control, and the others were intrinsically (blood) or extrinsically (coffee) stained. One stained specimen for each pigment was bleached with 35% hydrogen peroxide. The enamel was separated from the dentin, and the tooth color and translucency parameter (TP) were measured individually and after recombining these substrates. Changes in color (ΔE00), whitening index (WI), and TP caused by the staining and bleaching procedures were estimated through assessing the color differences compared with the controls. CTCC was also calculated by recombining the enamel and dentin tissues from different treatments. The data were analyzed using the paired t test or the two-way repeated measures ANOVA (α = 0.05).
Extrinsic staining procedures produced higher color changes than intrinsic ones, except in dentin. The highest bleaching effect was observed in the dentin of specimens that were extrinsically stained. Similar CTCC values were observed for the dentin and enamel for both the staining and bleaching procedures. Except for the specimens that were treated with intrinsic staining and became more translucent after the bleaching procedure, the other treatments resulted in non-significant TP changes.
Staining the specimens extrinsically resulted in higher color change than staining them intrinsically, and these specimens were more affected by the bleaching procedure. Enamel and dentin demonstrated similar CTCC values.
本研究评估了染色和漂白程序后牙本质和牙釉质的颜色和透明度变化，以及组织对颜色变化的贡献（CTCC）。
从牛切牙获取50个牙釉质 - 牙本质标本，根据基线颜色的相似性分为10组。每组中的一个标本用作对照，其他标本进行内源性（血液）或外源性（咖啡）染色。每种色素的一个染色标本用35%过氧化氢漂白。将牙釉质与牙本质分离，分别测量并在重新组合这些基质后测量牙齿颜色和透明度参数（TP）。通过与对照比较评估颜色差异，估计染色和漂白程序引起的颜色变化（ΔE00）、美白指数（WI）和TP变化。还通过重新组合不同处理的牙釉质和牙本质组织来计算CTCC。使用配对t检验或双向重复测量方差分析（α = 0.05）分析数据。
除牙本质外，外源性染色程序产生的颜色变化高于内源性染色程序。在外源性染色标本的牙本质中观察到最高的漂白效果。在染色和漂白程序中，牙本质和牙釉质的CTCC值相似。除了内源性染色处理且漂白后变得更透明的标本外，其他处理导致TP变化不显著。
外源性染色标本比内源性染色标本产生更高的颜色变化，并且这些标本受漂白程序的影响更大。牙釉质和牙本质表现出相似的CTCC值。
